Method of drawing metal shells



May 20, 1924.

c. c. JESSEN METHOD OF DRAWING METAL SHELLS Filed July 28 1922 2 so ipunch below the die.

Patented .May 20, 1924.

UNITED STATES 1,494,423 PATENT OFFICE.

CHARLES G.- JESSEN, Ol' WILMINGTON, DELAWARE, ASBIG-NOR. TO ATLAS POWDERCOMP-ANY, OF wmumeromnnmwm, A CORPORATION OI DELAWARE mission or maawmeMETAL exams.

Application fled. July 28 1922. Serial K0. 578,098.

To all whom it may concern:

Be it known that CHARLES C. J ESSEN, citizen of the United States,residing at Wilmington, in the county of New Castle and State ofDelaware, has invented certain new and useful Improvements in Methods ofDrawing Metal Shells, of which the following is aspecification.

This invention relates to a method of drawing metal shells. The methodconstituting the subject matter of the resent invention is not limitedto use in t e roduction of shells of any given kind since by this methoda wide variety of articles may be manufactured. However for purposes ofillustration I will describe it in con unction with the manufacture ofthe shells used in the manufacture of blasting caps or primers for theexplosives commonly used in blasting and like work.

In making shells it is customary to start with a cup-like piece of metaland to elongate this and reduce it to the desired thicknes bysuccessively forcing it through a number of dies by means of a punch,the thickness of the metal being reduced and the length of the shellbeing increased each time that it is forced through a die.- Heretoforethe material of the shell after being forced through the die has beenstripped from the punch upon upward movement of the punch by engagementof the upper end of the shell with the lower side of the die, thuscausing the shell to drop from the Since in drawing shells it isnecessary to subject them to a series of drawing operations in order tobring them to the desired length and thinness it follows that it is ofadvantage to have the shell stripped from the plunger above the die orwork-table where they may be readily grasped and carried on to the nextoperation. Where the shells have been stripped from the plungers belowthe die they have ordinarily been caused to fall into suitablereceptacles and must then be lifted above the work-table and broughtinto position to be operated upon by the succeeding die and plunger.Since, under conditions such as these, the o erator must select oneshell after the other rom a number of shells,'q it follows that theamount ofwork that can be accomplished in a day is considerably lessthan would be the case where the shell is delivered above the work tableready for the operator to grasp it.

It is a primary object of the present invention to provide a methodwhereby the shell will be caused to adhere to the punch during the timethat the punch is being returned through the die so that the shell willbe carried back through the die with the punch, the shell beingthereafter stripped as indicated at 10, and this cutting away orrelieving of the lower part of this opening constitutes an importantfeature of the invention. The punch 8 travels through a stripper element11 and upon upward 1110".8- ment of the punch 8 and shell 7 the upperend of the shell engages the lower end of the stripper element 11 and isstripped from the unch.

en the shell 7 is forced downwardly through the di 5 by the punch 8 theheat generated expands the metal of the shell at the drawing point butas soon as the shell leaves the die on its downward movement it shrinksonto the punch as it rapidly cools, with enough hold to allow the punchto pull it back through the die it was forced through, provided the diebe relieved or rounded out, as indicated at 10. The shrinking of theshell onto the punch in this manner causes the shell to grip the punchso tightly that upon the upward movement of the punch the shell will becarried back through the die and it is in this method of shrinking themetal of the shell onto the punch that the present inventionparticularly resides since as a result of this I am able to avoid theob'ections of those machines where the shell is stripped from the punchbelow the die.

Having described my invention what I claim is:

1. The herein described method which consists of forcing a shellentirely through a die by a punch of uniform diameter throughout itslength to a considerable distunee below said die expanding the metal ofthe shell by the act of forcing the same through the die, the cooling ofthe metal of the shell as it passes below the die contracting the sameupon the punch and then withdrawing the punch and shell through the diewhile the punch is gripped by the shell under such contraction.

2. The herein described method which consists of forcing a shellentirely through a die by a punch of uniform diameter throughout itslength to a considerable distancebelow said die expanding the metal ofthe shell by the act of forcing the same through the die, the cooling ofthe metal of the shell as it passes below the die contracting the sameupon the unch and then withdrawin the punch an shell throu h the die whie the punch is gripped by t e shell under such contraction andthereafter ati-ripping the shell from the punch above the die openingformed therein provided with 'fiaring mouths both at its upper and loweredges in combination with a unch of uniform diameter throughout itsoperating length adapted to be, passed through said opening and to exerta drawing action upon a shell as it is forced through said 0 ening, thelowermost flaring mouth facilitating the entrance of the upper edge ofthe shell into said die upon upward movement of the plunger, said shellbeing held upon said I plunger by its contraction after being forcedentirely through the die. In testimony whereof he aifixes his signaturein the presence of two witnesses.

- CHARLES C. JESSEN.

Witnesses: FREDERIO Boomer, J r.-, JEAN MoGAUeHAN.

3: In combination a die plate having 'a p

